1. Field of the Invention
The invention relates generally to the field of photography, and in particular to a film cassette containing roll film.
2. Description of the Prior Art
Commonly assigned U.S. Pat. No. 5,031,852, issued Jul. 16, 1991 discloses a film cassette wherein a film roll whose outermost convolution is a film leader is coiled about a spool core rotatable within the cassette shell in film unwinding and winding directions. A pair of flexible flanges are coaxially arranged on the spool core to radially confine the film leader within respective skirted peripheries of the flanges to prevent the leader from clock-springing against an interior wall of the cassette shell. A film stripper projects from the interior wall to be received between a leading end portion of the film leader and the next inward convolution of the film roll to free the leader from the flanges and guide it into a lighttight passageway to the exterior of the cassette shell responsive to rotation of the spool core in the unwinding direction. Thus, when the spool core is rotated in the unwinding direction, the film leader will be thrust or propelled from inside to outside the cassette shell.
Various means such as tape or a fastening hook may be devised for attaching an inner or trailing end portion of the film roll to the spool core. However, such known means have been found not to work well in the film cassette.